Known in the prior art are containers formed in a one-piece molded construction in which the container closure is coupled to the container neck by means of a frangible section. In order to permit removal of the contents from a container the closure is severed from the neck at the frangible section and the closure is removed.
Such containers are of great benefit in the medical field because they permit the low cost packaging of liquids in which sterility is necessary. Such containers are often manufactured in a streamlined operation that includes forming the container, filling the container with the sterile liquid, and sealing the container with a closure element fused to the bottle outlet. Such a seal forms a frangible line of weakness.
Most often, the means employed to open such a bottle includes an outer ring which includes internal threads which threadedly cooperate with external threads disposed on the neck of the bottle. Usually, a projection of some sort extends inwardly of the outer ring to engage part of the closure element. An example of such a system is seen in U.S. Pat. No. 4,176,755, assigned to the assignee of the present invention. To open the container, the outer ring is rotated either downwardly or upwardly depending on the design, to engage the closure element and break the frangible line of weakness.
Baxter Travenol Laboratories, Inc. of Deerfield, Ill., the present assignee, has found in its business that such containers, while highly successful, present a problem: the frangible line of weakness which enables the closure system to work is also susceptible to opening by unwanted forces during shipping and handling. As seen in FIG. 1 of the drawings, illustrating the prior art, a bottle 12 has a neck portion 14 defining an outlet 16. A closure element 18 is fused to the neck portion 14 at a line of weakness 20. A ring 22 is placed about the neck portion 14. The closure element 18 is indeed an easy target for receiving unintentionally applied forces occurring from the time of manufacture, including during shipping and in-hospital handling where the product is used. In an attempt to solve this problem, heavy cardboard cylinders 10 are manually placed over the neck and outer ring of the container for shipping. This procedure is expensive due both to the substantial cost of the cardboard cylinders and the cost of applying the cylinders to the containers. Also, the cardboard cylinders are useful only during shipping. They do not protect the frangible section 20 once the bottles are unpacked in the hospital.
The present invention is directed to an opening ring and closure system which protects the closure element from unintended opening during shipping and handling while eliminating the need for any additional piece, such as a cardboard packing cylinder. The apparatus of the present invention, unlike the packing cylinder, continues to protect the container seal in the hospital after the bottles have been unpacked.